Bump redis from 4.2.3 to 4.2.4

Bumps [redis](https://github.com/redis/redis-rb) from 4.2.3 to 4.2.4.
- [Release notes](https://github.com/redis/redis-rb/releases)
- [Changelog](https://github.com/redis/redis-rb/blob/master/CHANGELOG.md)
- [Commits](redis/redis-rb@v4.2.3...v4.2.4)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Gemfile.lock

@@ -65,7 +65,7 @@ GEM
     public_suffix (4.0.6)
     rainbow (3.0.0)
     rake (13.0.1)
-    redis (4.2.3)
+    redis (4.2.4)
     regexp_parser (1.8.2)
     rexml (3.2.4)
     rollbar (3.1.1)